饱和铁心型限流器限流阻抗试验和计算

Experimental and Analytical Study for Impedance of Saturated Iron-core Fault Current limiter

计算大电流下的阻抗值必须考虑铁心的非线性磁化特性。而实际铁心的磁化特性与铁心材料本身的磁化特性可能有一定偏差,这会导致计算的误差。本文根据系列限流铁心电抗器的实验结果,分析了电流大小、铁心绕组参数与限流器阻抗值的关系,并且给出了一种从小型试验样机实验结果中提取出铁心等效磁导率,进一步利用经验公式和拟合外延法来计算饱和铁心型限流器在大电流下阻抗值的方法。该方法简单易行,方法的准确性得到了不同尺寸限流器的实验验证。

For calculating the impedance,nonlinear magnetization property of the iron-core has to be considered. However,factual magnetization property of the iron-core might be different from that of the material used to make up it. This may lead to calculation errors. In this paper,based on the experimental results of the impedance of a serious of small iron-core reactors,we analyzed the relationship among the current rms value,the structure parameters and the impedance of fault current limiters. We proposed a method to calculating the impedance of iron-core fault current limiters at high current level. First,an equivalent permeability of ironcores is abstracted from the experimental results of small-size prototypes. Then,empirical formulas and curve fitting are employed to calculate the impedance of large-size limiters at high current level. Experimental results and calculating results are compared to examine the validity of the method.